Drilling machine



Oct. 4 .7

- 1927' G. H. GILMAN DRIMJNG MACHINE Q0 3 Sheets-Shee t 1 Filed Jan. 6,1921 Invenior:

7 3611 aaman.

Oct. '4, 1927.

- 1,644,120 G. H. GILMAN DRILLfNG MACHINE Filed Jan. 6. 1921 sSheets-Sheet 2 Oct. 4 1-927.

G. H. GlLMAN DRILLING MACHINE Filed Jan. 6, 1921 s Sheets-Sheet sInvenibr (1160719611. Gila van. gMM

Patented Oct. 4, 1927.

UNITED STATES v 1,644,12s PATENT OFFICE.

GEORGE E. GILMAN, F BELMONT, MASSACHUSETTS.

DRILLING MACHINE. I

My invention relates to drilling machines and particularly but notexclusively to a stopi'ng drill for rock.

The invention will be best understood from the accompanying drawings andthe .10 In the drawings following specification of a specific embodimentthereof submitted for illustrative purposes, while its scope will bemore particularly pointed out in the appended claims.

Figure 1 shows in elevation the submitted embodiment of the invention,with parts broken away; r

Fig. 2 is a vertical, longitudinal section on 15 an enlarged scale ofpart of the machine shown by Fig. 1, corresponding to a section on theline 2' 2 of Fig. 4;

' Figs. 3, 4C, 5, 6 and 7 respectively are sections on the lines 3'3,at-l, 55, 6-6 and E30 77 of: Fig. 2, Fig. 6 for illustrative purposesshowing the position of parts when the shafts driving the yokes havemoved ninety degrees vfrom the position illustrated by Fig.2;

Fig. 8 is a section on the line 8.8'of Fig. 2 with parts omitted;

Figs. 9 and 10 are diagrams representing the operation of the valvecontrolling the water supply for the drill steel and the a1r W for thefeed cylinder;

Fig. 11 is a section on the line 1'111 of Fig. 4;.

Fig. 12 is a section corresponding I to Fig. 11. with the valve moved toits neutral position; and

Fig. 13 is a. section corresponding to Fig. 11 with the valve moved tothe position in which the holev is blown.

Referring, to the drawings, the submitted embodiment of the inventiongenerally comprises: a drill. steel and fluid. pressure operated hammerfor moving it longitudinally, a vmotor for moving it angularly and afeeding device for moving it up to the work.

' The drill steel 1 is shown as provided with a shank 2 which isreceived by the chuck 3, the parts being so formed that when the chuckrotates,.thedrill steel must rotate with it as is usual indevices ofthis kind. As illustrated, aligned with the chuck is a ham.- mer havingthe head 1-, the rear extension 5 and the hammer bar 6,thelatter-projecting into the chuck and adapted to strike the:

oi the drill steelv atv the end of the tar the-hammerishank we. r d

Application filed January 6, 1921. Serial No. 435,474.

- invention.

The hammer is supplied with motive fluid through a passage 8 whichcommunicates with the forward portion of the bore receiving the rearwardextension 5 of the hammer and through passages 9 with the space at therearward end of this bore.

From an intermediate portion of the bore and connecting the samewith theforward portion of the bore receiving the head I of the hammer are shownpassages 10 which, when the hammer in its forward travel uncovers theirrearward end, admit pressure fluid to the forward portion of theborereceiving the head 4. Motive fluid is admitted to theroaij'wardportion of thebore receiving the head 4 at the end of the rearwardtravel of the hammer by reason of the reduced diameter portion 11 of theextension 5, estab lish'ing communication between suchport-ion and'theconduit 8 The intermediate portion of the bore receiving the head 4: isprovided with an exhaust port 12 in communication with a passage 13' forconducting the exhaust to the atmosphere. As'will be understood by thoseskilled in the art, exhaust willtake place when the head 4 in its,reciprocat ons opens the port 12 to opposite ends-of the, bore. I a IFor rotating the chuck by power means, the submitted embodiment of myinvention includes .a fluid operated rotary engine which as showncompris-esthel abutments lthand the rotor 15-. The details of thispartof the machine are not claimed in the present'application and willonly he described'with suflicient particularity to convey anunderstanding of their application .0 the submitted embodiment of theinvention. The rotor isjournaled on the exterior of thefcasing Icorresponding eccentrics of each shaftlI' mount the yokes 18 having.internal gear teeth that mesh with the external gear tel ll .20 formedon the chuck the e operation, the shaft?? an their eccentrics gyrate theyokes and rotate the chuck at a lesser speed than the shafts. By thisconstruction is afforded areduction gear.

Any suitable means may be provided for admitting motive fluid to therotary engine and exhausting it therefrom. For-this purpose asillustrated by Fig. 8 the intake conduits 21 are shown in communicationwith the constant pressure space at the rear end of the cylinder and theexhaust conduits 22 in communication with the ring-like chamber 23,which by means of a passage 23 is kept in communication with theatmosphere. Fig. 8 only shows the approximate position of the passages21 and 22, their true positions being shown in Figs. 4: and 5. It willbe noticed that the arrangement just described provides that wheneverthe hammer is supplied with motive fluid to cause it to reciprocate,motive fluid will be supplied to the rotary engine in order that it mayrotate the chuck.

The chuck, the hammer and the rotary engine just described are hereinhoused by a suitable casing providing a bearing forthe chuck and rotorand cylinders for the hammer and rotor. This casing as shown comprises afront head section or chuck casing 24, a main cylinder sect-ion 25, arear cylinder section 26, a motor casing or cylinder section 27 for therotor and a rear head block or section 28. It will be obvious that thecasingmay be divided to present sections more or less in number thanthose indicated.

For holding the sections of the casingin assembled relation I have atthe sides thereof four through bolts 29. As will be apparent, if the twolower bolts are removed for the purpose of attaching the machine to itsfeeding device as hereinafter described, the two upper bolts will holdthe sections in assembled relation.

The feeding means illustrated for m ving the drill steel and itsactuating mechanism up to the work comprises a cylinder 30 and a pistonor stoping bar which comprises the piston proper 81 and the piston rod32. The rearward end ofthe rod 32 is provided with an offset portion'33having the point 3a in alignment with the drill steel. The feed cylinderhas a front head 95 screwed into the cylinder, and a rear head 96secured to the cylinder by bolts 97. To prevent relative rotationbetween the rod 32 and the cylinder, the former is made polygonal incross-section and fits a similarly shaped opening in the head96. As willbe understood by those skilled in the art, the portion 33 is adapted tobe secured to a support, for example a mine column, or in the ordinaryworking of.

the machine as a stoper, a point 34 will engage the floor of a drift forenabling the drill steel to operate on the roof.

' The casing and feed cylinder are shown laterally offset from eachother, being herein arranged side by side in parallel relation'to afforda compact. machine enabling its use in drifts of limited head room. Ihave shown the intermediate portion of the casing in contact with theexterior of the cylinder, and for securing the casing to the feedcylinder have provided the latter with. spaced pairs of ears 35, whichare perforated to receive the projecting ends of the two lower bolts 29.In order to compensate for wear and inaccuracies of 'inanufacture, onthe forward projecting ends of the bolts 29 are shown sleeves 86, whichare received by the forwardly disposed ears and about the shoulderportions 37 of the chuck casing. When the bolts are tightened byscrewing up the nuts 88, the bolt heads 39 force the sleeves against theshoulders. 37 and the rear end of the casing against the rearwardlydisposed ears. This rlgidly connects the casing to the cylinder at onepoint, and at aspaced point slidably connects it to the'cylinder, andfurther provides an abutment at the rear end of the casing for taking upthe thrust of the feeding force.

For rotatin the machine manually I have shown the handle 40 providedwith a tapered porticn engaging a corresponding socket formed in thecasing. The handle is held in position by means of the lower bolts 29which engage suitable recesses 42 formed in the tapered portion of thehandle, which recesses provide surfaces extending the width of thehandle in contact with the bolts. It ill be observed by thisconstruction the handle is immovably keyed by the bolts to the casing.The nut a3 is provided to prevent movement of the handle when the bolt-sare removed and for binding the handle to the walls of the socket.

In order to permit manual rotation of the drill. steel by the handlejust described, it is necessary with the present construction to preventrotation of the chuck, and for this purpose herein is employed aclutchfor locking the chuck to its casing. .As shown the exterior surface ofthechuck has one or more recesses 44% adapted to be engaged by a bolt 45carried by the chuck casing. hen

the bolt is in the position ofparts shown by Fig. 7, the chuck will besecurely locked to the chuckcasing. For operating the bolt it has thetransversely disposed portion 46connecting the chuck engaging ortion tothe parallelly disposed portion 47 sliding in a perforated boss 48formed on the upper por tion of the chuck casing. The end of the portion47 is provided with a reduced diameter portion 49 androtatablymountedthereon is a sleeve 50 provided with a handle 51 andheld in position by the head 52 of the bolt and the shoulder 53 formedby the reduced diameter portion. tween the sleeve and the end of thecounterbored portion 54 of the boss is a spring 55 Interposed be i rtending to hold the bolt in engagement with the recesses of the chuck.By pressing the handle 51 inwardly, the bolt may, be'disengaged from thechuck and by releasing the handle the spring will automatically move thebolt into locking position. For holding the'bolt in its disengagedposition the ban die 51 slides through a suitable slot formed in. the.chuck casing, this slot as illustrated by Fig. 8', comprising theparallel portions 56 and 57 and the connecting portion '58. When thehandle is moved into itsinnermost position, it may be turnedtransversely relatively to the bolt and moved through the slot 58 intothe slot 57in which position it will be held by means of the spring andthe chuck "will then be free to rotate.

The drill steel I have shown provided with a bore 59 which extendsthroughout its length in order to conduct air andwater to the l olebeingdrilled for cleansingthe same. For conducting water to the drill steel 1have shown the tube 60 supported'in the back head and extending throughthe piston into the rearward end of. the drill steel. For supporting thetube in the back head I have shown the, latter as formed with arearwardly opening recess 61, said recess being closed a plug 62 whichsupports the swivelled water hose connection 63 and at its forward endabutsthe flange 64 of the water tube.

At the bottom of the recess and surround ing the end portion of thewater tube is shown the packing 65. p

Herein for controlling the supplies of fluid for operating the feedingmechanism, the hammer, the motor and the supplies of cleai' sing fluid.to the drill steel, are valves 66 and 67, respectively operated byhandles 88,- and 89. y V

Referring particularly to Figs. 25 3, 4t, 11, 12 and 13, the valve 66'is shown as of the turning plug type having its 'seat, in an extensionof the casing section 26,. The valve is snpplied with n otive fluidpreterably compressed air thrQug-hthehose connection 68, incommunication with. the space 69 at the righthand end of he valve asviewed by Fig. Formed in he. a e 'a;- ng udinal, passage 70 inv onstanommunicationwiih the, s ace 69 an .v p ci g. the p sage '70 incommunication with the exterior surface of the valve are the ports TlandThe valve is further provided with a transverse port. 73 hi h in theposition. of parts illustrated by Fig. 2,-places the xhaust pass.

sage 13 communication with a ,assage It in permanent communication. wlththe atmosphere. r

In the position. of parts; shown by Fig.2. motive fluid is. suppliedthrough, the passage 70 and ports. .72. to, supply. the hammer and thechuck rotating'mot or, while the exhaust from. the hammer is. permitted.o passffrom the exhaust'passage 13 through the port 73 and passage 74 tothe atmosphere. When the valve is moved to the position of parts shownby Fig. 13, the port 72 is moved out of communication with the passage 8into communication "with .the passage 13, to

which it supplies live motive fluid, which passes into the interior ofthe chuck through a passage 75 in communication with the of such sizethat in all positions of the valve the port will be in communicationWith'said passage. Air is admitted from the passage 76 to the feed. bymeans of the valve 67 p which likewise controls the; water.

'ihe valve 67 is of the turning plug type provided with a longitudinalpassage 77 having the. intersecting port 78 adapted to be moved into andout of communication with a passage '79placed in conmiunication with apassage 80 of the nipple 81 by means of the ring-shaped passage 82,which surrounds the conduits conducting water to the drill bit, asclearly illustrated Figs. 2

and 4. On the exterior portion of the throttle valve 67 and the sameplane as the transverse passage 78 is an arcuate pas- 83. adapted toplace the feed in comn'iunication w th the passage 84 leading to theatmosphere. Placing the water hose' con-' nection in. communication.with the valve seat is a passage indicated in its entirety at 85 in Fig.2 and placing the water tube in com; munication with the valve seat is asecont passage '86. 'For placing the passages 85 and 86' incommunication, the valve 67 is provided with the]longitudinallyextendingexterior, cavity 87. It will'rbe noticed by this construction that theairusupplied the passage 76 acts on the end surface of the 'vaijve 67 tohold it ito its seat and thereby prevents leakage of water and furtherany leakage which in spite of this may occur will be prevented by theair'pressure from leaking into the passages TG andTQJ I Figs. 9 and 10illustrate diagrammatically the operation of the valve 67'. In. thesefigures, the sectionsa5-a Z b,' correspond to sections on thelines. a-aand bb of Fig. 2. Fig. 9 illustrates. the position of parts when boththe steel. is'supplied with water and the feed issupplied with air. Inthis position. of, the parts, the groove 8*? establishes communicationbetween the intake and outlet passages 85 and. 86 for the water, whilethe passages 77 and '78sup' ly the port 79 leading to the feed cyl'n e'rwith air. In the position of parts shown by Fig. 10, the groove 87 ismoved out of communication with the water passages 85 and 86 and theport 78 is moved out of communication with the passage 79, under whichconditions air is no longer supplied the feed cylinder. In this positionof parts, the pasiage 79 is placed in communication with the atmospherethrough the passages 83 and 84 and the feed cylinder is exhausted. Thevalve 67 provides that the feeding pressure may be varied and for thispurpose the passages 78 and 83 in the submitted embodiment are soproportioned and relatively disposed that the feed cylinder may beopened more or less to the live air supply or to the atmosphere and eachto the exclusion of the other or to both simultaneously. This providesthat the supply may be throttled or by simultaneously throttling andexhausting a further reduction .in pressure may be secured, also thatthe air in the feed cylinder may be trappedand if desired its pressurefurther reduced by exhausting some of it. Depending on the-conditions ofoperation any of these may be effective to regulate the pressuremaintained in the feeding cylinder and the force of the feed.

It will be noted that in machines of this character the feeding forceholds the tool tightly against the rock and particularly in soft rockacts to prevent turning of the I steel. In order that the steel may bereadily turned it is of advantage that the air admitted to stop and thenadvance the hammer piston on its power stroke should move or tend tomove back the hammer cylinder to overcome or reduce the feedingpressure. With the present construction the constant pressure on thehammer extension 5 acts gradually to slow up the piston on its rearwardstroke, or in effect to reduce its inertia in such'manner that the airadmitted to the rear of the head 4 to stopand drive the piston forwarddoes not have the same effect in overcoming the feeding force as if theentire rearward surface of the piston were exposed to intermittentpressure. For this reason it is desirable to adjust the feedingpressureto suit the degree of throttling of the air supplied the hammerand the nature of the rock operated upon. It will be appreciated forexample that in soft rock the hammer must be throttled to reduce theforce of the blow, while the force. necessary to turn the steel must beincreased and at the same time the action of the hammer which overcomesthe feeding effort is reduced by and engaged in a suitable recess in thesocket.

Establishing communication between the nipple and, the forward end ofthe feed cylinder is a transverse passage 93and longitudinal passages 94opening into the feed cylinder at 94 This application disclosesimprovements upon the inventions disclosed by my pending applicationsSerial No. 421,748, filed November 4, 1920, Serial No. 442,094, filedFebruary 3, 1921., and Serial No. 407,773,

filed September 2, 1920.

Although for purposes of illustration I have described onespecificembodiment of is rotatably supported between oppositely facingportions of the work by a forwardly projecting drill steel and arearward support engaging part having, in combination, two parallelcylinders, one of said cylinders having therein a reciprocatory hammerpiston and having provision for non-rotatably cairrying the drill'steel,the other of said cylinders having means forming arelativelyreciprocable feed piston and feed piston rod, said rod being operativelyconnected to. a part for supporting the machine for rotation about theairialline of the drill steel, said part being non-rotatable relative tothe axis of the cylinder carrying said rod.

2. A drilling machine having, in combinaticn, a drilling tool and itsoperating mechanism, feeding means for said tool comprising extensible.telescopically arranged relatively non-rotatable fluid actuated members,the

outer of said telescopically arranged members being secured to saidmechanism in lateral ofiset relation thereto, the otherof said memberscarrying a part in substantial alignment with said tool, said. partbeing formed for rotatably engaging a support.

v3. A stoping drill having, in combination, a cylinder, a stoping barcarried by said cylinder in non-rotatable relation thereto, percussivemechanism carried by said cylinder in side by side relation thereto,said mechanism having means for carrying a drill steel,

a support engaging member carried by said bar and in operative alinmentwvith said steel, and means for bodily rotating said drill.

4. A stoping drill having,-in combination,

a relatively non-rotatable feed cylinder memi ber and stoping barmember, tool operating mechanism carried by one of said members in sideby side relation, a support engaging part carried by the other of saidmembers in alignment with the tool operated upon, and

means for bodily rotating said drill'for rov tating said tool. 5., Adrilling machine having, in combine tion, relatively non-rotatablecylinder and piston members, a drilling mechanism car ried by one ofsaid members in lateral offset relation thereto, said mechanism havingprovision for carrying a forwardly extending drilling tool and means forhammering and rotating said tool, and rearwardly arranged means formedfor rot-stably supporting the other of said-members in alignment withsaid tool.

6. The combination with a sectional percussive drill casing having sidebolts for securing the sections of said casing in assembled relation, offeeding means comprising a feed cylinder arranged parallel to saidcasing, and means for detachably securing said casing and cylindertogether, said means preventing substantially relative movementbetween'said casing and cylinder and includ ing attaching means carriedby said cylinder for engagement with part onlyof said bolts, wherebysaidcasing may be detached from saidcylinder while holding said sections inassembled relation.

7. In a drilling machine, a percussive apparatus comprising a sectionalcasing having side bolts for securing the casing sectionsin assembledrelation, cooperating feed cylinder and piston members, said cylindermember being arranged beside said casing and rigidly carryinglongitudinally spaced perfor-ated ears,part.only of said side bolts passing through said ears for substantially rigidly securing said casing andcylinder member together and for permitting detachment of said casingfrom said cylinder member while holding said sections in assembledrelation. 1

'8. A' drilling machine having, in combination, means for carrying adrilling 'tool,

means for imparting percussion to said tool and for rotating it,'acasing for said means, an extensible fluid operated feeding "device forsaid tool comprising a feed'cylinder arranged inside by side relation tosaid casing anddetachably secured thereto, a feed pisto'n and a feedpiston rod non-rotatable'relative-tosaidcylinder and adapted to supportthe machine in alignment with said tool.

9. A drilling machine having, in combinationfpercussive apparatusincluding a casing housing a hammer piston and chuck for a drillingtool, a motor for rotating said chuck comprising a motor casingcarried'by ,said first mentioned casing, a feeding means for said toolcomprising a cylinder and a cooperating piston, said cylinder beingarranged in side by side relation to said casing and motor, a pluralityof side bolts for securing said motor casing to said first mentionedcasing, and means engaging part only of said side bolts for securingboth casings to said cylinder, whereby said cylinder'may be detachedfrom said casings'while holding the latter in assembled relation.

-10. A drilling machine having, in combination, parallel feed-andpercussive casings arranged in side by side relation, a laterallyprojecting nipple carriedbyoneof said casings and a cooperating socketatthe side 9f the other of said casings, means for holding saidcasings'in relatively fixed assembled relation, and conduitsforconduc-ting motive fluid formed in said casings and communicatingwith eachother-through said nipple and socket. I

11. A drilling machine having, in ce1nbination, a feed cylinder and apercussive casing arranged in side by side relation motive fluidconducting conduits formed in each and opening through registering portsin facing sides, means establishing a {mid tight connection between saidports-means for securing said casingsubstantiall rigidly to said feedcylinder, and -a feed in said feed cylinder having a rod for engagementwith an abutment.

12. A drilling machine having, in com bination, a toolactuatorcomprising sections,

through bolts holding said sectionstogethe'r,

feeding means for said actuator comprising a iced cylinder, meansforming a rigid nection between part'only of said bolts and saidcylinder, and a Sliding connection spaced from said rigid connectionbetween saidb olts and feeding means,

13. A drilling machine having, in "combination, tool actuator comprisingparts held in assembled relation by a through bol -t projecting beyondsaid casing at opposite ends, feeding means comprising a feed cylinderfor said actuator, spaced substantially radially projecting ears carriedby said cylinder, one of said ears receiving the projecting end portionof said bolt, a sleeve carried by the'o'positely projecting end portionor said bo t, said sleeve received-by another of said earsyand means fovtightenening saidbolt to draw the sleeve-and first named ear againstsaidcasing.

'14. A drilling machine having, in combination, meansv for carrying-adrillingtool, an actuator forsaid tool, fluid pressure actuatedfeeding-means comprising cylinder-and piston members,-one of saidmembers carrying said actuator-din lateral offset relation thereto,theother of said membersbein'g-operatively connected to means torengaging asupport, said means being non-rotatablerelative to the membercarryingsaid actuator and providing for rotation of saidmember about theaxial'line of said tool,

15. A drilling machine having, in combination, a tool actuator providedwith means for carrying a forwardly projecting drilling tool, a rearwardly extending feed piston and rod, the latter arranged in nonrotatable telescopic relation to a forwardly located feed cylinder, saidcylinder carrying said actuator in lateral offset relation'thereto, saidrod having means for coacting with a support for supporting the machinefor rotation about the axial line of said tool, and means providing arotation handle for the machine.

16. A stoping machine having, in combination, an impact engine havingprovis on for carrying a hollow drill steel pro ect ng from its forwardend, an extensible feeding device having a cylinder upon the side ofwhich said impact engine is mounted, said cylinder having mountedtherein a reciprocatory piston projecting from the rearward end of saidcylinder, means preventing said piston from rotating relative to saidcylinder, a tube carried by said impact engine for conducting cleansingfluid for passage through said hollow drill steel, said tube beingremovable through the rearward end of said impact engine, said pistoncarrying a supporting portion offset to place it coaxial- 1y of saiddrill steel;v said offset portion being so placed as to provide, whenthe feeding device is extended, sufficient clearance between it and therearward end of said impact engine to permit said tube to be removed.

17. A stoping machine having, in combination, means for carrying ahollow drill steel, an extensible fluid actuated feeding mechanismhaving support engaging means in alignment with said steel, an impactengine supported by said hollow drill steel and support engagingmechanism, said impact engine having a tube for conducting cleansingfluid for passage through said hollow drill steel, said tube beingremovable through the rearward end of said impact engine while saidengine is attached to said feeding mechanism.

' 18. A rock drilling machine having, in combination, an impact enginehaving provision for carrying a hollow drill steel, a tube forconducting cleansing fluid for passage through said hollow drill steel,a feedingdevice for said impact engine, said feeding device having acylinder and a piston one ofWhiOh is connected to said impact engine forfeeding it and the other of which is arranged to cooperate with asupport for the machine located at the rear of said actuator inalignment with said steel, said feeding device being so disposed withrelation to said impact engine that said tube may be removed through therearward end of said impact engine while the latter is connected to saidfeeding device.

19. A stoping machine having, in combination, a hammer drill having achuck formed for carrying a hollow drill steel, a fluid actuatedtelescopic feeding device having a support engaging portion aligned withsaid drill steel, said hammer drill being supported by said drill steeland said feeding device, a tube extending axially through said hammerdrill for conducting cleansing fluid from the rearward end to theforward portion thereof for passage through said drill steel, and aconnection between said feeding device and hammer drill permitting saidtube to be removed through the rearward end of said hammer drill whilethe latter is attached to said feeding device.

20; A stoping machine having, in combination. an impact engine foractuating a drill steel, a fluid actuated feeding device having acylinder secured to said engine in lateral offset relation thereto, apiston in said cylinder, a piston rod for said piston movablelongitudinally of said cylinder but secured against substantial rotationrelative to said cylinder, said rod having a rock en gaging point inalignment with the axis of the drill steel, a removable water tubeextending through said engine, and means for detachably securing saidtube at one end thereof to the rearward end of said engine,

said means permitting removal of saidtube through the rearward end ofsaid engine.

21. A stoping machine having, in combination, an impact engine foractuating a drill steel, a fluid actuated feeding device having acylinder secured to said engine in lateral offset relation thereto, apiston in said cylinder, a piston rod for said piston movablelongitudinally of said cylinder but secured against substantial rotationrelative to said cylinder, said rod having a rock engaging point inalignment with the axis of the drill steel, a removable water tubeextending through said engine, and means for detachably securing saidtube at one end thereof to the rearward end of said engine, said meanspermitting removal of said tube through the rearward end of said engineand comprising a removable plug carried by said engine at the rearwardend thereof.

22. A stoping machine having, in combination, an impact engine foractuating a drill steel, a fluid actuated feeding device having acylinder secured to said engine in lateral offset relation thereto, apiston in said cylinder, a piston rod for said piston movablelongitudnially of said cylinder but secured against substantial rotationrelative to said cylinder, said rod having a rock engaging point inalignment with the axis of the drill steel, a removable water tubeextending through said engine, means for detachably securing said tubeat one end thereof to the rearward end of said engine, said meanspermitting removal of said tube through the rearward end of said engineand comprising a removable plug carried by said engine at the rearwardend thereof, and a water connection carried by said plug.

23. A stoping machine ,having, in combination, an impact engine foractuating a drill steel, a fluid actuated feeding device having acylinder secured to said engine in lateral ofiset relation thereto, apiston in said cylinder, a piston rod for said piston movablelongitudinally of said cylinder but secured against substantial rotationrelative to said cylinder, said rod'having a rock engaging point inalignment With the axis of the drill steel, a removable Water tubeextending through said engine, and means for detachably securing saidtube at one end thereof to the rearward end of said engine, said meanspermitting removal of said tube through the rearward end of said engineand comprising a plug removably secured to said engine at the rearwardend thereof, one end of said plug adapted to secure said tube and theother end adapted to carry a Water connection.

24. A stoping machine of the type Wherein the tool actuator is adaptedto be supported between an oppositely extending tool and feedingmechanism by engagement of the tool and feeding mechanism Withoppositely facing surfaces of the Work comprising, in combination, adrill steel, a fluid actuated hammer engine for actuation of said steel,a feed cylinder carried by said engine in lateral oli set relationthereto, a feed piston in said cylinder, a feed piston rod for saidpiston, said rod movable longitudinally of said cylinder but securedagainst rotation relative to said cylinder, and a Work engaging end .forsaid rod offset into alignment With said drill steel.

25. A stoping machine of the type wherein the tool actuator is adaptedto be supported between an oppositely extending tool and feedingmechanism by engagement of the tool and feeding mechanism Withoppositely facing surfaces of the Work comprising, in combination, afluid actuated hammer engine for actuating a drill steel, a feed cylinder carried by said engine in lateral offset reiation thereto, a feedpiston in said vcylinder, a feed piston rod for said piston,

said rod movable longitudinally of said cyl inder but secured againstrotation relative to said cylinder, a Work engaging end for said rodoliset into alignment with said drill steel, said end adapted to permitrotation of the machine relative to the Work, a chuck rotatably carriedby said engine, said chuck termed for substantially non-rotatablyreceiving the shank of said drill steel, a fluid actuated motor andreduction gearing carried by said engine for actuating rotation of saidchuck relative to said engine, and releasable means efi'ective toprevent rotation of said chuck relative to saidengine.

In testimony whereof, I have signed my nameto this specification.

GEORGE H. GILMAN.

CERTIFICATE OF CORRECTION.

Patent No, 1,644,120, Granted October 4, 1927, to

GEORGE H. GILMAN.

It is hereby certified that error appears in the printed specificationof the above nnmhereti patent requiring correction as follows: Page 2,line 36, after the word "have" insert the word "shown"; page 6, line114, claim 22, for the misspelien were "longitunially" read"longitudinally"; and that the said Letters Patent should he read withthese corrections therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this 1st day of November, A. D. 1927.

M. J. Moore,

Seat. Acting Commissioner of Patents.

